/drivers/crypto/padlock-sha.c

  1/*
  2 * Cryptographic API.
  3 *
  4 * Support for VIA PadLock hardware crypto engine.
  5 *
  6 * Copyright (c) 2006  Michal Ludvig <michal@logix.cz>
  7 *
  8 * This program is free software; you can redistribute it and/or modify
  9 * it under the terms of the GNU General Public License as published by
 10 * the Free Software Foundation; either version 2 of the License, or
 11 * (at your option) any later version.
 12 *
 13 */
 14
 15#include <crypto/internal/hash.h>
 16#include <crypto/sha.h>
 17#include <linux/err.h>
 18#include <linux/module.h>
 19#include <linux/init.h>
 20#include <linux/errno.h>
 21#include <linux/interrupt.h>
 22#include <linux/kernel.h>
 23#include <linux/scatterlist.h>
 24#include <asm/i387.h>
 25#include "padlock.h"
 26
 27#ifdef CONFIG_64BIT
 28#define STACK_ALIGN 16
 29#else
 30#define STACK_ALIGN 4
 31#endif
 32
 33struct padlock_sha_desc {
 34	struct shash_desc fallback;
 35};
 36
 37struct padlock_sha_ctx {
 38	struct crypto_shash *fallback;
 39};
 40
 41static int padlock_sha_init(struct shash_desc *desc)
 42{
 43	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
 44	struct padlock_sha_ctx *ctx = crypto_shash_ctx(desc->tfm);
 45
 46	dctx->fallback.tfm = ctx->fallback;
 47	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 48	return crypto_shash_init(&dctx->fallback);
 49}
 50
 51static int padlock_sha_update(struct shash_desc *desc,
 52			      const u8 *data, unsigned int length)
 53{
 54	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
 55
 56	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 57	return crypto_shash_update(&dctx->fallback, data, length);
 58}
 59
 60static int padlock_sha_export(struct shash_desc *desc, void *out)
 61{
 62	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
 63
 64	return crypto_shash_export(&dctx->fallback, out);
 65}
 66
 67static int padlock_sha_import(struct shash_desc *desc, const void *in)
 68{
 69	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
 70	struct padlock_sha_ctx *ctx = crypto_shash_ctx(desc->tfm);
 71
 72	dctx->fallback.tfm = ctx->fallback;
 73	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 74	return crypto_shash_import(&dctx->fallback, in);
 75}
 76
 77static inline void padlock_output_block(uint32_t *src,
 78		 	uint32_t *dst, size_t count)
 79{
 80	while (count--)
 81		*dst++ = swab32(*src++);
 82}
 83
 84static int padlock_sha1_finup(struct shash_desc *desc, const u8 *in,
 85			      unsigned int count, u8 *out)
 86{
 87	/* We can't store directly to *out as it may be unaligned. */
 88	/* BTW Don't reduce the buffer size below 128 Bytes!
 89	 *     PadLock microcode needs it that big. */
 90	char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
 91		((aligned(STACK_ALIGN)));
 92	char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
 93	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
 94	struct sha1_state state;
 95	unsigned int space;
 96	unsigned int leftover;
 97	int ts_state;
 98	int err;
 99
100	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
101	err = crypto_shash_export(&dctx->fallback, &state);
102	if (err)
103		goto out;
104
105	if (state.count + count > ULONG_MAX)
106		return crypto_shash_finup(&dctx->fallback, in, count, out);
107
108	leftover = ((state.count - 1) & (SHA1_BLOCK_SIZE - 1)) + 1;
109	space =  SHA1_BLOCK_SIZE - leftover;
110	if (space) {
111		if (count > space) {
112			err = crypto_shash_update(&dctx->fallback, in, space) ?:
113			      crypto_shash_export(&dctx->fallback, &state);
114			if (err)
115				goto out;
116			count -= space;
117			in += space;
118		} else {
119			memcpy(state.buffer + leftover, in, count);
120			in = state.buffer;
121			count += leftover;
122			state.count &= ~(SHA1_BLOCK_SIZE - 1);
123		}
124	}
125
126	memcpy(result, &state.state, SHA1_DIGEST_SIZE);
127
128	/* prevent taking the spurious DNA fault with padlock. */
129	ts_state = irq_ts_save();
130	asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
131		      : \
132		      : "c"((unsigned long)state.count + count), \
133			"a"((unsigned long)state.count), \
134			"S"(in), "D"(result));
135	irq_ts_restore(ts_state);
136
137	padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
138
139out:
140	return err;
141}
142
143static int padlock_sha1_final(struct shash_desc *desc, u8 *out)
144{
145	u8 buf[4];
146
147	return padlock_sha1_finup(desc, buf, 0, out);
148}
149
150static int padlock_sha256_finup(struct shash_desc *desc, const u8 *in,
151				unsigned int count, u8 *out)
152{
153	/* We can't store directly to *out as it may be unaligned. */
154	/* BTW Don't reduce the buffer size below 128 Bytes!
155	 *     PadLock microcode needs it that big. */
156	char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
157		((aligned(STACK_ALIGN)));
158	char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
159	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
160	struct sha256_state state;
161	unsigned int space;
162	unsigned int leftover;
163	int ts_state;
164	int err;
165
166	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
167	err = crypto_shash_export(&dctx->fallback, &state);
168	if (err)
169		goto out;
170
171	if (state.count + count > ULONG_MAX)
172		return crypto_shash_finup(&dctx->fallback, in, count, out);
173
174	leftover = ((state.count - 1) & (SHA256_BLOCK_SIZE - 1)) + 1;
175	space =  SHA256_BLOCK_SIZE - leftover;
176	if (space) {
177		if (count > space) {
178			err = crypto_shash_update(&dctx->fallback, in, space) ?:
179			      crypto_shash_export(&dctx->fallback, &state);
180			if (err)
181				goto out;
182			count -= space;
183			in += space;
184		} else {
185			memcpy(state.buf + leftover, in, count);
186			in = state.buf;
187			count += leftover;
188			state.count &= ~(SHA1_BLOCK_SIZE - 1);
189		}
190	}
191
192	memcpy(result, &state.state, SHA256_DIGEST_SIZE);
193
194	/* prevent taking the spurious DNA fault with padlock. */
195	ts_state = irq_ts_save();
196	asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
197		      : \
198		      : "c"((unsigned long)state.count + count), \
199			"a"((unsigned long)state.count), \
200			"S"(in), "D"(result));
201	irq_ts_restore(ts_state);
202
203	padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
204
205out:
206	return err;
207}
208
209static int padlock_sha256_final(struct shash_desc *desc, u8 *out)
210{
211	u8 buf[4];
212
213	return padlock_sha256_finup(desc, buf, 0, out);
214}
215
216static int padlock_cra_init(struct crypto_tfm *tfm)
217{
218	struct crypto_shash *hash = __crypto_shash_cast(tfm);
219	const char *fallback_driver_name = tfm->__crt_alg->cra_name;
220	struct padlock_sha_ctx *ctx = crypto_tfm_ctx(tfm);
221	struct crypto_shash *fallback_tfm;
222	int err = -ENOMEM;
223
224	/* Allocate a fallback and abort if it failed. */
225	fallback_tfm = crypto_alloc_shash(fallback_driver_name, 0,
226					  CRYPTO_ALG_NEED_FALLBACK);
227	if (IS_ERR(fallback_tfm)) {
228		printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
229		       fallback_driver_name);
230		err = PTR_ERR(fallback_tfm);
231		goto out;
232	}
233
234	ctx->fallback = fallback_tfm;
235	hash->descsize += crypto_shash_descsize(fallback_tfm);
236	return 0;
237
238out:
239	return err;
240}
241
242static void padlock_cra_exit(struct crypto_tfm *tfm)
243{
244	struct padlock_sha_ctx *ctx = crypto_tfm_ctx(tfm);
245
246	crypto_free_shash(ctx->fallback);
247}
248
249static struct shash_alg sha1_alg = {
250	.digestsize	=	SHA1_DIGEST_SIZE,
251	.init   	= 	padlock_sha_init,
252	.update 	=	padlock_sha_update,
253	.finup  	=	padlock_sha1_finup,
254	.final  	=	padlock_sha1_final,
255	.export		=	padlock_sha_export,
256	.import		=	padlock_sha_import,
257	.descsize	=	sizeof(struct padlock_sha_desc),
258	.statesize	=	sizeof(struct sha1_state),
259	.base		=	{
260		.cra_name		=	"sha1",
261		.cra_driver_name	=	"sha1-padlock",
262		.cra_priority		=	PADLOCK_CRA_PRIORITY,
263		.cra_flags		=	CRYPTO_ALG_TYPE_SHASH |
264						CRYPTO_ALG_NEED_FALLBACK,
265		.cra_blocksize		=	SHA1_BLOCK_SIZE,
266		.cra_ctxsize		=	sizeof(struct padlock_sha_ctx),
267		.cra_module		=	THIS_MODULE,
268		.cra_init		=	padlock_cra_init,
269		.cra_exit		=	padlock_cra_exit,
270	}
271};
272
273static struct shash_alg sha256_alg = {
274	.digestsize	=	SHA256_DIGEST_SIZE,
275	.init   	= 	padlock_sha_init,
276	.update 	=	padlock_sha_update,
277	.finup  	=	padlock_sha256_finup,
278	.final  	=	padlock_sha256_final,
279	.export		=	padlock_sha_export,
280	.import		=	padlock_sha_import,
281	.descsize	=	sizeof(struct padlock_sha_desc),
282	.statesize	=	sizeof(struct sha256_state),
283	.base		=	{
284		.cra_name		=	"sha256",
285		.cra_driver_name	=	"sha256-padlock",
286		.cra_priority		=	PADLOCK_CRA_PRIORITY,
287		.cra_flags		=	CRYPTO_ALG_TYPE_SHASH |
288						CRYPTO_ALG_NEED_FALLBACK,
289		.cra_blocksize		=	SHA256_BLOCK_SIZE,
290		.cra_ctxsize		=	sizeof(struct padlock_sha_ctx),
291		.cra_module		=	THIS_MODULE,
292		.cra_init		=	padlock_cra_init,
293		.cra_exit		=	padlock_cra_exit,
294	}
295};
296
297static int __init padlock_init(void)
298{
299	int rc = -ENODEV;
300
301	if (!cpu_has_phe) {
302		printk(KERN_NOTICE PFX "VIA PadLock Hash Engine not detected.\n");
303		return -ENODEV;
304	}
305
306	if (!cpu_has_phe_enabled) {
307		printk(KERN_NOTICE PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
308		return -ENODEV;
309	}
310
311	rc = crypto_register_shash(&sha1_alg);
312	if (rc)
313		goto out;
314
315	rc = crypto_register_shash(&sha256_alg);
316	if (rc)
317		goto out_unreg1;
318
319	printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n");
320
321	return 0;
322
323out_unreg1:
324	crypto_unregister_shash(&sha1_alg);
325out:
326	printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
327	return rc;
328}
329
330static void __exit padlock_fini(void)
331{
332	crypto_unregister_shash(&sha1_alg);
333	crypto_unregister_shash(&sha256_alg);
334}
335
336module_init(padlock_init);
337module_exit(padlock_fini);
338
339MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
340MODULE_LICENSE("GPL");
341MODULE_AUTHOR("Michal Ludvig");
342
343MODULE_ALIAS("sha1-all");
344MODULE_ALIAS("sha256-all");
345MODULE_ALIAS("sha1-padlock");
346MODULE_ALIAS("sha256-padlock");